(57) Abstract:Long-wavelength VCSEL laser in accordance with the present invention is optically connected to the short-wave electrically pumped VCSEL laser and optically pumped them.The short wavelength radiation emitted from the upper surface of the underlying VCSEL laser, passes through the lower mirror of the long-wavelength VCSEL laser. Longwave radiation is preferably emitted from the upper surface of the long-wavelength VCSEL laser. Two laser VCSEL preferably connected together using a transparent optical adhesive material (adhesive), by fusing layers or metal soldering. Technical results is to obtain high output powers, the emission wavelength of the VCSEL laser at 980 nm wavelength laser, 1300 or 1550 nm. 2 S. and 19 C.p. f-crystals, 18 ill. The invention relates mainly to an integrated semiconductor lasers and mainly to lasers with optical pumping and surface emitting vertical cavity surface-emitting (VCSEL).Art
VCSEL is a semiconductor laser comprising a semiconductor layer of optically active substances, such as, for example, and is and was highly reflective layers of metal material, dielectric material, bipolar grown semiconductor dielectric material, and combinations thereof, mirrors are often multi-layered stacks. As is customary, one of the mirror stacks partially reflective to direct a portion of coherent light generated in the resonant cavity formed by sandwich the active layer between the reflective stacks.Laser patterns require optical limitations in the cavity and limitations of carriers, in order to achieve efficient conversion of electron pumping in stimulated photons through the inverse of the populations. Standing wave reflected electromagnetic energy in the resonator has a characteristic cross-section that defines the amplification of electromagnetic fashion. Desirable electromagnetic fashion is a singleton (only) main fashion, for example HE11fashion cylindrical waveguide. Single-mode signal from the VCSEL laser is easily connected with optical fiber has a low divergence and essentially single-mode laser.In order to achieve lasing threshold, the total amplification of the VCSEL must balance its total loss is their leads to the requirement that effective lasers VCSEL mirrors must have a reflectance higher than approximately 99.5 percent. This requirement is much more difficult to perform for the long-wavelength VCSEL lasers than for short-wavelength VCSEL lasers, since mirrors can be grown in the same epitaxial manner as the active area. For example, in 980-nm laser VCSEL on GaAs mirrors can be grown using alternating layers of GaAs and AlGaAs. Since the difference of refractive index between the two materials is 0.6, then we only need a few layers to produce a suitable mirror. For a similar design mirrors for 1300 or 1550 - nm VCSEL laser should be applied alternating layers of InP and InGaAsP. However, in this case, the difference in refractive index is approximately 0.23. As a result, the mirror of InP/InGaAsP must be much thicker to achieve the same reflectivity as that of the mirror GaAs/AlGaAsP. However, increasing the thickness in practice does not work, because the loss due to absorption and diffraction are also increasing, certainly limiting the maximum achievable reflectivity.Therefore, in order to form a suitable DL is eat semiconductors with mismatched lattices. Fig. 1 and 2 illustrate two possible combinations of the mirrors described in the prior art. Both structures use at least one mirror of GaAs/AlAs, which has a large difference of refractive indices than that of InP/InGaAsP. Fusion of the layers is a well - known technology, with which the semiconductors with different lattice constants can be connected at the atomic level, simply by applying mechanical pressure and heat. The structure shown in Fig. 1, is used as the upper mirror electrically insulating dielectric mirror 3, while the structure shown in Fig. 2, is used as the top mirror, another mirror 2 of GaAs/AlGaAs obtained by fusing layers.Patterns of lasers VCSEL shown in Fig. 1 and 2, have several disadvantages associated with electrical injection of charged carriers in the active zone. The structure in Fig. 1 has an insulating dielectric upper mirror 3, which leads to the requirement of contact with the metal ring 4 and the injection around the dielectric mirror 3 by way of injection 5. Such contact and injection scheme is the result of a complex production technologies. The structure shown in Fig. 2, the ISP who provides active resistance and makes a significant ohmic heating. Since the optical efficiency materials such as InP and InGaAsP, as is known, quickly degrades with increasing temperature, ohmic heating will limit the output power of the device. Finally, patterns of lasers on both figures 1 and 2, as well as any other electrically injected laser VCSEL require p - and n-impurities inside the optical resonator. Impurities still make a loss, which of course limits the power output.Alternative electrical pumping is optical pumping. Optical pumping eliminates complicated technology, ohmic heating and the loss introduced by doping. One of the known approaches, which was used for short-wavelength VCSEL laser, operating at 860 nm, described in the article "Vertical Cavity Surrface-Emittinq Semiconductor Laser with CW Injection Laser Pumping", IEEE Photonics Tech. Lett., 2 (3) (March 1990), S. 156-158. It uses a grill built in-plane semiconductor lasers as pump sources for one wavelength of the VCSEL laser. In another known approach to optical pumping of the structure of the long-wavelength VCSEL laser, consisting of 30 pairs of compressed pressure cracks and deformed by stretching the barriers, and Si/SiO2dielectric mirrors, sing Strain-Compensated Multiple Quantum Wells", Appi. Phys. Lett. 64(25) (20 July 1994), S. 3395-3397. Any of the above well-known approaches or any other approach using or planar semiconductor laser or laser dyes, or pumped solid-state laser, are not suitable for commercial production of VCSEL lasers. Virtually commercial VCSEL lasers should have the possibility of mass production and control in order to have a clear commercial advantage over in-plane semiconductor lasers.From the foregoing it is obvious that there is a need for a compact long wavelength VCSEL laser with optical pumping, which can be done and checked on a massive scale.The invention
The present invention provides long-wavelength VCSEL laser, which is optically pumped by the short-wavelength VCSEL laser. Long-wavelength VCSEL laser in accordance with the present invention optically connected and optically pumped VCSEL laser with a shorter wavelength and with an electric pump. The short wavelength radiation emitted from the upper surface of the underlying VCSEL laser, passes through the lower mirror of the long-wavelength VCSEL laser. In a preferred embodiment, a length of the public joined together using a transparent optical adhesive, by fusing layers or soldering of metals.In one embodiment, the short-wavelength VCSEL laser radiation at 980 nm and the long wavelength VCSEL laser emits at 1300 or 1550 nm. Long-wavelength VCSEL laser uses either pure mirror GaAs/AlAs or from AlGaAs/AlAs fused layers or dielectric mirror formed of alternating layers of SiO2and TiO2or any other combination of dielectrics.Long-wavelength VCSEL lasers, which emit both 1300 nm and 1550 nm, pumped lasers VCSEL at 960 nm, especially suitable for fiber-optic communication systems. As separate devices, these long-wavelength VCSEL lasers can displace expensive lasers with distributed feedback in low-power applications. Arrays (matrices), these lasers open up the possibility for parallel transmission of data over long distances, or through the light guide cable or division - simultaneous modulation of multiple VCSEL lasers into a single optical fiber (light guide). One - or two-dimensional lattice is also applicable to the relationship in a free optical space.In another embodiment, two laser VCSEL split mechanical seal. The number of microlenses of GaAs, is formed directly in the second VCSEL laser. This option applies to achieve high output powers, as for the optical pumping wavelength laser VCSEL small diameter can be used short-wavelength laser VCSEL large diameter. The microlenses of the GaAs you can replace the individual microlenses of different materials.In Fig. 1 shows schematically a known electrically injected laser VCSEL at 1300/1550 nm from the top dielectric mirror,
in Fig. 2 - known electrically injected laser VCSEL at 1300/1550 nm with two fused mirrors of GaAs/AlGaAs,
in Fig. 3 - in General the present invention,
in Fig. 4 - the present invention in which a pair of long-wavelength VCSEL lasers are connected with a pair of short wavelength lasers VCSEL with optical glue,
in Fig. 5 - the present invention in which a pair of long-wavelength VCSEL lasers are connected with a pair of short wavelength lasers VCSEL by fusing layers,
in Fig. 6 - the present invention in which the lower mirror the long-wavelength VCSEL lasers grown in the same way as mirrors shortwave lasers VCSEL,
in Fig. 7 is another variation of the present invention,
in Fig. 8 - the present invention that uses the combined mi is nowym lasers VCSEL using a metal brazing,
in Fig. 10 - the present invention in which both the lower and upper mirrors the long-wavelength VCSEL lasers use dielectrics,
in Fig. 11 - the present invention that uses lateral oxidation,
in Fig. 12 is a graphic reflection coefficient of the mirror GaAs/AlAs mirrors and SiO2/TiO2,
in Fig. 13 - specific variant of the long-wavelength VCSEL laser, suitable for use in the present invention,
in Fig. 14 is a detailed diagram of the energy bands in the preferred design of the absorbing filter for the variant of the present invention according to Fig. 13,
in Fig. 15 is a graph of gain for a single quantum gap InGaAs,
in Fig. 16 is a graph of the dependence of output power on the pump power for a specific variant of the present invention,
in Fig. 17 is a variant of the present invention, in which long-wave radiation from a pair of long-wavelength VCSEL lasers extends in the direction opposite to the pumping radiation, and
in Fig. 18 is a variant of the present invention, similar to the variant according to Fig. 17, except that the long-wavelength VCSEL lasers are slightly angled to the short-wavelength VCSEL lasers.An alternative to the system the desired radiation. The injected light is absorbed in the long wavelength resonator, generating electrons and holes. These charge carriers then diffuse into the quantum slit and re-emit at a higher wavelength. Because optical pumping does not require electrical contacts, the production is much simpler and does not occur ohmic heating. In addition, since the media injectively light, the light can be entered by using mirrors. In the electric circuit pump injection should occur around the mirror, assuming that the mirror is electrically insulating. Moreover, in the optical pumping schemes resonator can be free from impurities, while impurities are the main source of optical losses in the laser VCSEL.Fig. 3. depicts in General the structure of the present invention. This figure, as well as the subsequent Fig. 4-7, 9-11 and 17-18, depicts two shortwave laser VCSEL 43, optical pumping two long-wavelength laser VCSEL 40. This structure is not intended to limit, and to the schematic image of mass (conveyor) nature of the production technology. The same technology can be used to make a single device that consists of a single wavelength laser tx2">Lasers 43 are a pair of electrically pumped short wavelength VCSEL lasers. They contain short-wavelength active region 31 located between the short-wave mirrors 32. Shortwave radiation is emitted from the upper surface 33 of the laser VCSEL 43 in the lower surface of the second pair of lasers VCSEL 40. Lasers VCSEL 40 are a pair of long-wavelength VCSEL lasers, containing long-wavelength active region 35 located between the lower mirror 36 and the upper mirror 37. Mirrors 36 and 37 are far. The mirror 36 is transparent to shortwave radiation emitted by the VCSEL lasers 43. Longwave radiation is emitted from the upper mirror 37. The modulation wavelength is accomplished by modulating the short wavelength pump lasers VCSEL. In a modified embodiment, the modulation is performed by application of contacts to the long-wavelength VCSEL laser.Fig. 3 and subsequent structural diagrams depict the lower mirror 32 shortwave lasers VCSEL top mirror 37 long-wavelength VCSEL lasers vertically etched to form a cylindrical posts. These hours are divided initially flat layer on many devices, specifies the index prelomleniya, implantation, diffusion, recrystallization, or selective breeding. In the preferred embodiment, both short-wave and long-wave lasers VCSEL must be with a controlled refractive index, while the short-wavelength VCSEL lasers can be controlled by strengthening or thermally.The structure of the optical pumping of Fig. 3 in General retains the advantages of the VCSEL laser, such as the possibility of mass production and control and cheap production of one - or two-dimensional matrices. This greatly contrasts with the VCSEL lasers, which are used as optical pumping of solid state lasers, dye lasers, or in-plane semiconductor lasers. Optically pumped VCSEL lasers that use these these approaches impractical for matrix applications, and cannot be produced and monitored on a massive scale.Fig. 4 depicts one of the variants of the invention. Long wavelength lasers VCSEL 40 is used fused layers of pure mirror 41 of GaAs/AlAs on the bottom side, and a dielectric mirror 42 on the upper side. Dielectric mirror 42 are formed of alternating layers of silicon dioxide SiO2and titanium dioxide TiO2. Diele is to short wavelength lasers VCSEL 43 with a transparent optical adhesive (adhesive) between the GaAs substrates 45 and 46. Fig. 5 essentially represents the same version of the invention, and Fig. 4, except that the substrate 45 long-wavelength lasers VCSEL 40 of GaAs attached by fusing layers to a substrate of GaAs 46 shortwave lasers VCSEL 43 on the interface (interface) 50. This approach eliminates the need for optical glue, probably reducing spurious reflections. In the modified embodiment shown in Fig. 6, the mirror of GaAs/AlAs 41 can be grown in the same epitaxially way as lasers VCSEL 43, thereby eliminating the need for any optical adhesive 44 or alloying layer 50 on this interface.Fig. 7 depicts a diagram of a modified variant of the invention. Long wavelength lasers VCSEL 40 contain long-wavelength active area 60 located between two mirrors 61 of GaAs/AlAs. The active area 60 is attached by fusing layers of mirrors 61 at the interface 62. In this embodiment, the obtained two-fuse structure is connected to the optical adhesive 44 to the short wavelength VCSEL lasers 43. Received two fuse structure may also be joined by fusing layers of the VCSEL lasers 43, as shown in Fig. 5.Fig. 8 depicts a variant of the invention that uses integrated micrococci number of long-wavelength lasers VCSEL 40. However, in this embodiment, a matrix (lattice) lasers VCSEL split mechanical seal 70. Between the two types of lasers there are a number of microlenses 71 of GaAs, which are used to focus the radiation from the laser 43 on lasers 40. The microlenses 71 are formed directly on a substrate of GaAs 72 short-wave laser (shown) or directly on a substrate of GaAs wavelength lasers VCSEL (not shown), or both. Thus, short-wavelength laser VCSEL large diameter can be used for optical pumping wavelength laser VCSEL small diameter. This structure allows to achieve high output powers in the long wavelength VCSEL laser. In a modified embodiment, the microlenses 71 are formed from materials other than GaAs, such as glass or capable of back flow" of the polymer. In this modified structure the microlenses 71 United not integral with the other parts of the device.Fig. 9 illustrates a different technique to attach the long wavelength lasers VCSEL 40 to shortwave lasers VCSEL 43. In this approach, two pairs of lasers VCSEL is connected to the metal interface 75 by means of a metal solder. The number of Windows 76 in metal interface allows the passage of radiation from the pump. Microlens maguuma, the preferred implementation uses either palladium or indium containing solder.Fig. 10 depicts a variant of the invention, in which the lasers VCSEL 40 dielectric mirror 80 and 81. Using optical adhesive 44 to connect the lasers VCSEL 40 to lasers VCSELS 43, this option does not require the use of the process of fusing the layers.In a modified embodiment, the dielectric mirror 81 is attached to the laser VCSEL 43 using a known technique in connection with dielectric semiconductor.In a variant of the invention, depicted in Fig. 11, the long-wavelength active region 60 is located between the dielectric mirror 42 and the bottom of the mirror 90. The mirror 90 is formed by epitaxial growing alternating layers of InP and InAlAs. For final finishing of the mirror structure is etched from the sides of InAlAs material. Aluminum in InAlAs then oxidized at the edges, creating a connection InwAlxAsyOzthat has a refractive index much lower than that of InAlAs or InP. In discouraged mirror turns into was highly reflective mirror. Technology lateral oxidation can also be performed with compounds containing aluminum and antimony. Fig. 12 from the Oia, in which the short-wavelength VCSEL lasers 43 emit at 980 nm, and the long-wavelength VCSEL lasers emit 40 at 1550 nm. Graph 100 is the reflectance of the mirrors of the GaAs/AlAs suitable for the bottom mirror of the VCSEL laser 40. This mirror transmits at the wavelength of pumping and reflects on the wavelength of the laser 40. Graph 101 is the reflectance of the dielectric mirrors of SiO2/TiO2suitable for the top mirror of the VCSEL lasers 40. The dielectric mirror may be designed so that either pass or reflect the laser wavelength VCSEL 43. If the dielectric skips at this wavelength, as shown in the graph 100, lasers VCSEL 40 see only one pass of the radiation from the pump lasers VCSEL 43. If the dielectric reflecting at the wavelength of the pump (not shown), then the lasers VCSEL 40 see two passes radiation from lasers pump 43. Making the dielectric mirror is partially reflecting, it is possible to design a two-pass configuration, which increases the absorption, and therefore, the pumping efficiency. It is also possible to make both the top and bottom mirrors the long-wavelength VCSEL lasers partially reflective at the wavelength of the pump, creating a resonant absorption and increase the efficiency of the pump. This last coner VCSEL, suitable for use in the present invention. Two quantum slit 110 coherent lattice InGaAs placed on two peaks of the optical standing wave. Quaternary InGaAsP material 111 surrounding these cracks, absorbs radiation pumping and draws the charge carriers in the gap, where they re-emit at 1550 nm. The absorption coefficient of the material of the procedure 1.5104cm-1so for shows lengths (0.7 μm) 90 percent of the incident radiation is absorbed in two passes through the resonator. Fig. 13 shows that the long-wavelength resonator has a larger transverse dimension 112 than the transverse size of the pump 113. This not only provides a more efficient conversion of pump radiation long-wave radiation, but also single-mode transverse mode long wavelength VCSEL laser. In a preferred variant of realization of the transverse size of 112 long-wavelength VCSEL laser is determined by the lateral change of the refractive index (i.e., by setting the refractive index). The variation of the metric may be determined in any or all vertical layers of the device, and can be performed by chemical etching, recrystallization, implantation, diffusion, disordering, selective growth or other technologies. the displays detailed diagram of the energy zones of the preferred construction of the absorbing filter for option, it is shown in Fig. 13. The vertical axis of this diagram is the vertical distance in the structure, and the horizontal axis represents the relative energy. Graph 114 shows the energy levels as a function of the vertical distance to the valence band. Schedule 115 shows the energy levels as a function of the vertical distance to the conduction band. In this embodiment absorbing material 111 composition is selected to create a built-in electric field. Built-in electric field is configured such speed and efficiency with which photogenerated charge carriers are collected in the quantum slits 110. In this design the absorber 111 contains a composition selected InGaAsP 116 and 117. Part 116 are selected from a material with a band gap of from 1.15 μm at the bottom and up to 1.3 mm at the top. Part 117 is selected from materials with a bandgap from 1.3 μm at the bottom and up to 1.15 μm is at the top. The barrier layer 118 of InP is shown in this diagram. Although Fig. 13 and the following calculations assume the quantum slit with coherent lattice, the ideal quantum slit 110 is relatively compressed in comparison with the surrounding layers.Power at the wavelength of 1550 nm compared to the power at the wavelength of 980 n is iconv[T/(T+A)],
wherei= fraction of injected photons, recombining radiantly in cracks;
conv= energy loss from 980 nm to 1550 nm = 980/1550 = 0.63;
T = the relative transparency of the output mirror at 1550 nm;
A = the percentage of light loss by absorption/scattering/diffraction in a single pass;
Pth= the capacity of the pump required to achieve the threshold.The threshold power of the pump can be calculated using the dependence of the gain of the quantum slit shown in Fig. 15. To reach the threshold, the quantum slit should provide amplification in a single pass return equal to the losses for the same passage, which constitute T + A. Since the resonator does not contain alloying additives, loss absorption/scattering/diffraction in a single pass can be very small, approximately 0.1 percent. At a predetermined transparency on the yield of about 0.3 percent, the threshold gain is 0.4 percent.If both slits pumped the same, then this assumption is acceptable for two-pass absorption that each slit should provide amplification in a single pass round - trip of about 0.2 percent, or 0.1 percent in a single pass. Given the width of the slot 80 of angs what about the value can be converted to the desired current density or power density by means of Fig. 15. Because Fig. 15 does not contain periodic growth gain 2 when quantum cracks are at the peak of the standing wave, the approximate value for gain per unit length will be 1250/2 = 625 cm-1. In accordance with Fig. 15, to achieve a gain of 625 cm-1the current density should be 270 A/cm2. Complete the required current density is 540 A/cm2because there are two quantum cracks or absorbed power density should be 680 watts/cm2. Assuming that is absorbed 85% of the pump radiation, the threshold need 800 watts/cm2. If this power is evenly distributed over the 10-micrometer-diameter VCSEL laser, then the total power required to reach threshold, will amount to 0.6 mW. Because some of the injected carriers can diffuse light around the optical industry, the number of injected carriers that are required to achieve the threshold will be higher than the calculated one. Therefore, in order to compensate the lost media power threshold is close to 1 mW.Fig. 16 depicts a graph of equation (1) wheni= 0.85 andconv= 0.63. Fig. 16 shows that for this particular variant of the invention the output power of pinacate, to improve the efficiency of absorption or use of a higher average gain, you can increase the output power. Large output power can also be obtained by using the structure shown in Fig. 8.A plot of the output power from the input power in Fig. 16 shows in a large range of power as linear. Typical based electrically pumped VCSEL laser show fluctuations (deviations from straight line) due to heating on large control currents. This effect is not shown in Fig. 16, since the heat during the optical pumping is much less than the electric pump. For example, thermal resistance in the structure shown in Fig. 4, is about 1K on mW. This means that 1 mW of heat received in the cavity, will lead to a temperature increase of 1K. In the example above, the required capacity of the pump 4 mW to generate output power wavelength of about 1 mW. Even if all the remaining 3 mW translate into heat, which is unlikely, then the result may be a temperature rise in the long-wave resonator only 3 K. In significant contrast, in electrically pumped VCSEL you can expect an increase in the temperature is extended in the direction the opposite direction of the pump radiation. Fig. 17 depicts a diagram of a possible structure for this option. In this structure shortwave active area 31 is located between two short-wave mirrors 85 and 86. Mirror 86 reflects almost 100 percent of short-wave radiation, but substantially transparent to long-wave radiation. In the modified structure, schematically shown in Fig. 18, the long-wavelength VCSEL lasers 40 are slightly tilted towards the short wavelength VCSEL lasers 43. The inclination of the two matrices allows long-wave radiation to pass by shortwave mirrors 86.For professionals it is clear that the present invention can be implemented in other specific embodiments without departure from the nature and characteristics of the latter. Accordingly, the description of the preferred variants of the invention are not intended to limit, and for illustration of the invention, which is discussed below by the claims. 1. The optical device containing the first laser is a vertical cavity with the radiating surface (VCSEL) having a long wavelength active medium is located between the first mirror and the second mirror, slucare, than the first wavelength, wherein the second VCSEL laser optically pumps the first laser VCSEL.2. The optical device under item 1, characterized in that it contains means for electrical modulation of the second VCSEL laser and modulation of the second VCSEL laser modulates the first laser VCSEL.3. The optical device under item 1, characterized in that it contains means for electrical modulation of the first laser VCSEL.4. The optical device under item 1, characterized in that the first and second mirrors pass radiation at the second wavelength.5. The optical device under item 1, characterized in that the first mirror passes radiation at the second wavelength, and the second mirror reflects radiation at the second wavelength.6. The optical device under item 1, characterized in that at least one of the specified first and second mirrors of the first laser VCSEL is formed of alternating layers of materials selected from the group of gallium arsenide, aluminum arsenide, aluminum gallium arsenide and aluminum arsenide, as well as the fact that the mirror is attached by fusing layers to far-active environment.7. The optical device under item 1, characterized in that P> 8. The optical device under item 1, characterized in that at least one of the specified first and second mirrors are formed of alternating layers of indium phosphide, aluminum-arsenic oxide India.9. The optical device according to p. 1, wherein the first VCSEL laser alloyed layer with a second laser VCSEL.10. The optical device under item 1, characterized in that it contains a layer of optical adhesive on the boundary surface between the first laser VCSEL and the second VCSEL laser.11. The optical device under item 1, characterized in that the first laser VCSEL is connected with the second laser VCSEL using a metal brazing.12. The optical device under item 1, characterized in that the connecting material metal brazing contains a solder containing indium.13. The optical device under item 1, characterized in that the first mirror of the first laser VCSEL is formed of alternating layers of gallium arsenide and aluminum arsenide, and the first mirror and the second laser VCSEL grown in a single epitaxial growth process.14. The optical device under item 1, characterized in that the first wavelength of approximately 1300 nm and the second wavelength is approximately 980 nm.15. Op is equal to about 980 nm.16. The optical device under item 1, characterized in that the first laser VCSEL has a first optical fashion with the first cross-section, and the second laser VCSEL has a second optical fashion with a second cross-section, and the first cross section is greater than the second cross-section.17. The optical device under item 1, characterized in that the first laser VCSEL has a first optical fashion, some lateral variation of the refractive index.18. The optical device under item 17, characterized in that the lateral variation of refractive index is formed by chemical etching, by recrystallization, implantation, diffusion, or selective disordering growing.19. The optical device under item 1, characterized in that it contains a mechanical seal between the first laser VCSEL and the second VCSEL laser and at least one microlens of gallium arsenide disposed between the first laser VCSEL and the second VCSEL laser focusing the radiation from the second laser VCSEL at first VCSEL laser.20. The optical device under item 1, characterized in that the first wavelength of the active medium contains a first set of layers that absorb the second wavelength, and a second set of layers with quantum is usausa surface (VCSEL), causing the radiation at the first wavelength emitted from the first VCSEL laser, characterized in that it includes the introduction of radiation in the first VCSEL laser at the second wavelength of the second laser VCSEL, which is shorter than the first wavelength.
SUBSTANCE: proposed laser comprises high-voltage pulse generator, transfer line, chamber with electrodes and solid state laser target. Said target consists of plane-parallel solid state plate and dielectric substrate with one or several orifices. Dielectric substrate and solid state plate are interconnected via dielectric interlayer used to rule out breakdown in air gap between surfaces of aforesaid plate and substrate. Substrate dielectric constant is smaller than that of solid state plate. One electrode of said laser is arranged on the side of solid state plate, while the other one can move on the side on dielectric substrate and has one or several orifices aligned with those in substrate.
EFFECT: stabilised generation zone and chances to generate simultaneously in several zones of solid state plate.
6 cl, 2 dwg
SUBSTANCE: semiconductor laser emitter includes a laser crystal with positive and negative electrical leads and an electrical input unit with a coplanar microwave transmission strip line formed on a dielectric substrate. The laser crystal is connected to earthing leads of the coplanar microwave transmission strip line by negative leads, and by the other lead to the signal track of the same coplanar microwave transmission strip line. In the laser crystal, the positive and negative leads are made on one side with leads of one polarity lying between loads of the other polarity. The laser crystal is installed via "reverse mounting" and is soldered to the end the coplanar microwave transmission strip line formed on the dielectric substrate. The coplanar microwave transmission strip line lies under the laser crystal so as to match corresponding leads of the laser crystal and the signal and earthing strips of the coplanar microwave transmission strip line.
EFFECT: wider modulation band.
SUBSTANCE: laser electron beam device includes an electron gun, electron beam focusing and deflecting systems and a laser screen. The screen includes a plane-parallel semiconductor plate with reflecting coatings on its surface. The device also includes a microwave deflecting system between the electron gun and the deflecting system, and a slot mask made from electron-absorbing material placed on the laser screen on the side of the electron beam. The semiconductor plate is made from semiconductor materials with different wavelength of the generated radiation in regions lying on different sides of an arbitrary bridge of the slot mask.
EFFECT: possibility of generating synchronised picosecond laser pulses at two wavelengths with possibility of scanning the laser radiation within limits determined by the size of the laser screen.
SUBSTANCE: heterostructure based laser contains waveguide layer placed between wide-gap emitters of p and n-conductivity type that are simultaneously the limiting layers, active zone consisting of quantum-dimensional active layer, optical Fabry-Perot cavity and stripe ohmic contact under which the injection zone is located. In the waveguide layer outside the injection area there is the introduction of the area of semiconductor material with the width of energy gap that is less than the width of energy gap of active area. The factor of optical confinement of closed mode of abovementioned semiconductor material fits the ratio: where: - values of the compounds of optical confinement factor G for closed mode in the introduced area of semiconductor material with the width of energy gap that is less than the width of energy gap of active area, relative units; αNB - optical losses related to interband absorption of closed mode radiation in the introduced area of semiconductor material with the width of energy gap that is less than the width of energy gap of active area, cm-1.
EFFECT: increase of output optic power in both continuous and pulse current injection mode, as well as increased time stability of output active power.
13 cl, 4 dwg
SUBSTANCE: heterostructure-based laser has a waveguide layer enclosed between wide-gap emitters with p and n conductivity type, which are simultaneously bounding layers, an active region consisting of quantum size active layer, an optical Fabry-Perot resonator and a strip ohmic contact with an injection region underneath. In the waveguide layer outside the injection region there is a doped region, where the optical limiting factor of the closed mode in the doped region and concentration of free charge carriers in the doped region satisfy the relationship: where: is the value of the component of the optical limiting factor GY in the amplification region for the closed mode, arbitrary units; is the mode loss at the output of the Fabry-Perot resonator, cm-1; αi is loss due to absorption on free charge carriers in the amplification region, cm-1; Δα denotes losses associated with closed mode radiation scattering on irregularities (αSC), inter-band absorption (αBGL) and absorption on free charge carriers in lateral parts of the injection laser, cm-1; is the closed mode optical limiting factor in the doped region, arbitrary units; n, p denote concentration of free electrons and holes in the doped region, respectively, cm-3; σn, σp denote the absorption cross-section on free electrons and holes in the doped region, respectively, cm2.
EFFECT: high optical power output in both continuous and pulsed modes of current pumping, high stability of the output optical power.
13 cl, 5 dwg
SUBSTANCE: laser has an active plane with a mirror coating on the first surface which is attached to a first cold-conducting substrate, an external feedback mirror and a pumping laser. The active plate lies between the mirror coating and the external feedback mirror, which are elements of the optical resonator of the disc laser. The pumping laser has its own stable optical resonator and the wavelength of its radiation is shorter than that of the disc laser. The active plate of the disc laser is one of the reflecting elements of the stable optical resonator of the pumping laser, wherein during reflection of radiation generated in the pumping laser from the active plate, part of the radiation is partially absorbed in the active plate, thereby exciting the disc laser.
EFFECT: high power of radiation and wider spectral range.
23 cl, 9 dwg
SUBSTANCE: invention relates to quantum electronics and electronic engineering and can be used in devices with a scanning light beam. The laser electron-beam tube is in form of a vacuum flask with an exit optical window and has an electron-optical axis along which are series-arranged an electron source, electrode system for forming an electron beam and an active plate with a highly reflective coating on its first surface, which is mounted on a cold-conducting substrate. Electron-beam focusing and deflecting systems are placed outside the tube. The flask houses reflecting elements in form of a concave reflector with an optical axis and a flat reflector which, along with the highly reflective coating, form the optical resonator of the laser electron-tube beam with the active plate inside said resonator. The optical window of the flask is a flat reflector with a reflecting coating on the inner surface, which is highly reflective on part of said surface and partially transmitting on the other part of the surface for radiation of the active plate.
EFFECT: improved directivity and high power of the scanning laser beam.
12 cl, 3 dwg
FIELD: physics, optics.
SUBSTANCE: invention relates to laser engineering. The disc laser consists of an optical cavity with a first optical axis, an active plate having a first surface and a second surface, placed inside the optical cavity and mounted on a cooling substrate by its first surface, a pumping laser, a pumping laser radiation focusing system and a multi-pass optical pumping system. The pumping system is a semi-concentric cavity with a single external reflector with a concave mirror surface, having a second optical axis and characterised by a focal distance where at double the focal distance from the external reflector, perpendicular to the second optical axis, there is a reflecting layer and a mirror coating of the a flat reflector. The focusing system is placed between the pumping laser and the active plate such that the radiation beam of the pumping laser is directed towards the plate at an incidence angle greater than half the bean convergence angle, and is focused into an excitation spot near the point of intersection of the second optical axis and the second surface of the active plate, excluding said point. The centre of the excitation spot lies at a distance from said point which is greater than a quarter of the diameter of beam of the pumping laser at twice the focal distance from the excitation spot.
EFFECT: simple device, higher reliability of the device and a wider spectral range owing to reduced heating of the active heterostructure.
15 cl, 8 dwg
SUBSTANCE: method and realising devices, are based on peculiarities of semiconductor laser emitters, consisting in fact that with increase in temperature of radiator for maintaining output parameters (power, radiation force) at required for operation level is necessary to increase operating current at reduced temperature of radiator is necessary to reduce operating current. Voltage at capacitive energy storage unit varies when measuring temperature of the radiator at preset law, which provides passage through radiator pumping current required to maintain radiation power in required for operation range.
EFFECT: technical result is simplification of method and device for pumping semiconductor laser emitter, which provide maintenance of radiation power within certain limits at action of destabilising factor of temperature.
4 cl, 10 dwg
SUBSTANCE: surface-emitting laser device with a vertical external resonator with optical pumping contains, at least, one VECSEL and several pumping laser diodes. VECSEL includes one Brega mirror. The outside mirror is the second resonator mirror, from which the pumping laser diode radiation is reflected, arranged around the active area of VECSEL and which provides a multiple re-reflection of the generated VECSEL radiation.
EFFECT: simplifying the alignment of the pumping lasers relative to the active VECSEL area, and ensuring the compactness of the laser device structure.
12 cl, 10 dwg
FIELD: electrical engineering.
SUBSTANCE: proposed active element comprises heterostructure built around semiconductor compounds selected from groups A2B6 or A3B5. Active structure is arranged between upper and lower limiting semiconductor layers that make, together with active structure, an optical waveguide. Said active structure comprises at least two alternating superfine semiconductor layers with different refraction factors and at least one active layer arranged between aforesaid two layers that has higher refraction factor than that of alternating layers. Note here that upper and lower limiting layers have higher refraction factor compared with layers of active structure. Thickness h of upper limiting layer satisfies the condition h<x, where x is the depth of electron beam penetration into active structure. Outer surface of upper limiting layer has corrugated relief with direction of corrugations perpendicular to active element optical axis. Note here that relief spacing equals whole number of half-waves of laser radiation in active layer material. Note also that corrugation depth does not exceed height h of upper limiting layer.
EFFECT: higher output power.
3 cl, 4 dwg, 1 ex
SUBSTANCE: holder for depositing optical coatings on sets of strips of light-emitting elements has a base with a window for the support element and has guide clamping elements made in form of prismatic bars whose working planes lie on butt-ends of their cross section; a support element and a locking mechanism. The support element is at an angle (0-45)°, and dimensions of the cross profile of the clamping element are related to the thickness of the strip of the light-emitting element, the number of strips in a set and the number of sets in the holder by an expression.
EFFECT: broader technological capabilities of the holder for depositing optical coatings, higher quality of products and cost-effectiveness of production.
1 tbl, 5 dwg
SUBSTANCE: dipole nanolaser for generating coherent electromagnetic radiation includes a two-level system in form of a quantum dot and a coherent electromagnetic radiation resonator. The resonator, which has a metal or semiconductor nanoparticle and electrocontact plates, has one more nanoparticle which lies from the said nanoparticle and from the said quantum dot at distances less than wavelength of the coherent electromagnetic radiation generated by the said nanolaser. Both nanoparticles are capable of exciting dipole oscillation modes in antiphase at the frequency of the said coherent electromagnetic radiation.
EFFECT: higher Q-factor of the resonator of the dipole nanolaser.
1 dwg, 1 ex
SUBSTANCE: resonator has circular section and is made in the form of a revolution solid. The revolution solid comprises an active area, facing layers and a part of a substrate. A generatrix of the side surface of the revolution solid is inclined relative to the normal line of a heterostructures.
EFFECT: possibility to output radiation, which is wideband by wave length, in vertical direction.
SUBSTANCE: device includes at least one multilayer interference reflector and at least one resonator. In one version of the invention implementation the reflector works as a modulating element controlled by the voltage applied thereto. The stop zone edge is subjected to adjustment using electrooptic methods due to quantum-limited Stark effect in proximity to resonant mode which creates modulation of the reflector transmission factor thus entailing indirect modulation of light intensity. In another version of the invention implementation the optic field profile in the resonator represents the stop zone wavelength shift function, the device working as adjustable wavelength light radiator. In yet another version of the invention implementation at least two periodicities of refraction factor distribution are created in the reflector which enables suppression of parasitic optical modes and promotes high-speed direct modulation of intensity of light emitted by the device.
EFFECT: vertically integrated optoelectronic device serving for high-speed data transfer by way of direct or indirect modulation of emitted light intensity.
11 cl, 34 dwg
SUBSTANCE: semiconductor infrared source includes a semiconductor substrate (1) with two optically connected and geometrically spaced-apart disc resonators (2) or annular resonators (10) in form of a heterostructure. On the surface of the semiconductor substrate (1) lying opposite the surface with the disc resonators (2) or annular resonators (10) there a first ohmic contact (3). A second ohmic contact (8) is deposited on the face of the corresponding disc resonator (2) or annular resonator (10). The distance from the outer edge of the second contact to the inner edge of the resonator is not more than 100 mcm. The disc resonators (2) or annular resonators (10) lie from each other at a distance L or overlap in the region of waveguides at a depth D, said distance and depth satisfying certain relationships.
EFFECT: simple design and reducing optical loss during single-mode oscillation in the middle infrared spectrum.
2 cl, 14 dwg
FIELD: physics, optics.
SUBSTANCE: invention relates to dipolar nanolaser arrays. The device includes a substrate having an active layer, a transparent conducting layer, a transparent dielectric layer and metal nanoparticles-nanoantennae. The nanoantennae are stretched - one dimension exceeds the other two dimensions. Electromagnetic coupling of the emitters of the active layer with the nanoantenna array is provided by selecting optimum distance between the active layer and the nanoantennae. Injection pumping is used to generate radiation.
EFFECT: high efficiency, realising a continuous mode, providing narrow generation lines, small dimensions of the device, high reliability of the device and low pumping power threshold.
5 cl, 1 dwg
SUBSTANCE: semiconductor light-emitting device comprises a white optically transparent body coated with a phosphor on the walls. Inside the housing is a laser diode having an axis of symmetry. Wherein the laser diodes are arranged in series on the axis of symmetry of the light emitting devices so that their axes of symmetry coincide. Ends of laser diodes are connected so that they are in electrical and mechanical contact and form an array of laser diodes, the radiation pattern of which has an axis of symmetry coincident with the axis of symmetry of the light emitting device.
EFFECT: technical result is to provide a semiconductor white light emitting device of high intensity light without increasing the size of light-emitting elements, thus providing uniform illumination of the phosphor.
2 cl, 9 dwg